The technical scope of the invention is that of devices allowing a muzzle mirror to be fastened to one end of an artillery barrel.
The purpose of muzzle mirrors is to supply the artillery fire control with the true position of the end of the barrel.
Indeed, the thermal stresses resulting from the firing as well as the meteorological conditions cause a variable strain of the gun barrel (generally called bending).
However, the external ballistics (and therefore firing accuracy) is linked to the true position of the muzzle of the barrel. Firing accuracy will thus be strongly affected by the bending of the barrel and the fire control must possess the accurate co-ordinates of the barrel muzzle so as to control laying appropriately.
The muzzle mirror is a polished surface that receives a laser beam emitted by the fire control. This mirror reflects the beam, a sensor on the fire control picks up the reflected beam and thereby determines the true position of the barrel muzzle depending on the deviation measured.
Known fastening devices for muzzle mirrors generally incorporate fastening flanges that encircle the gun barrel. They present the drawback of badly withstanding the stresses due to firing (recoil accelerations and vibrations), such stresses being all the greater in that the barrel of the gun generally incorporates a muzzle brake that rejects part of the propellant gases to the rear, thus towards the mirror. The radial and/or axial position of the mirror is thus gradually modified and the firing reference measured becomes incorrect.
So as to overcome such drawbacks, the mirror is sometimes welded to the barrel. However, such an arrangement complicates the installation of thermal sleeves and smoke boxes onto the barrel. Indeed, these elements can no longer be designed in the shape of cylindrical barrels slipped over the barrel but must be constituted by two half-shells assembled using toggle fasteners.
Moreover, welding imposes the choice of a material for the mirror support analogous to that constituting the barrel thereby leading to the definition of a heavy mirror support increasing the bending of the barrel.